Momona Ethiopian Journal of Science

First occurrence of rudderfish Centrolophus niger (Gmelin, 1789) in the Edremit Bay (Northern Aegean Sea, Türkiye) with the maximum length record for Turkish Seas

2023-11-04T16:05:55+00:00

Climate change is one of the crucial factors affecting the geographical distribution of fish species. However, the maximum size is an indication of whether there is overfishing pressure on a fish species or the current ecological conditions in which it is located. A single specimen of recently died (rigor mortis has not yet formed) Centrolophus niger was incidentally found inshore on January 27, 2023, off the Burhaniye coast (Edremit Bay, Northern Aegean Sea, Türkiye). The present study indicates both the first observation of C. niger for Edremit Bay and its maximum length for Turkish seas.

Meat Yield and the Length–Weight Relationships of the Narrow‐Clawed Crayfish, Pontastacus leptodactylus (Eschscholtz, 1823)

2023-11-04T16:22:50+00:00

The present study investigated the length-weight relationships and meat yield of narrow-clawed crayfish, Pontastacus leptodactylus (Eschscholtz, 1823), in Kocahıdır Irrigation Reservoir. Between July 2015 and June 2016, a total of 653 individuals (255 females and 398 males) were sampled, and their carapace lengths (CL), total lengths (TL), and total weights (TW) were measured. The female-to-male ratio for the entire population was found to be 0.64:1.00. The results showed that the CL of the narrow-clawed crayfish ranged between 37 and 90 mm (39-79 mm for females and 37-90 mm for males), while the TW ranged from 10.10 to 165.61 g (11.13-90.01 g for females and 10.16-165.61 g for males). The TL of female individuals was 114.09 mm, with a weight of 40.43 g, while the TL of male individuals was 116.32 mm, with a weight of 53.45 g. The ratio of individuals above the minimum legal-size limit of 100 mm was determined to be 80.70% for the crayfish population in Kocahıdır Irrigation Reservoir. Regression analysis indicated that the TL-TW and CL-TW relationships for female narrow-clawed crayfish exhibited negative allometric growth, while males showed positive allometric growth in terms of the TL-TW relationship and isometric growth in terms of the CL-TW relationship. Isometric growth was observed in the whole population for both male and female individuals in terms of TL-TW and CL-TW characteristics. Female individuals with carapace lengths ranging from 43-82 mm had a chelae meat yield of 2.48%, an abdomen meat yield of 11.38%, and a total meat yield of 13.85%. Male narrow-clawed crayfish with carapace lengths ranging from 35 to 90 mm had a chelae shear meat yield of 4.13%, an abdomen meat yield of 10.52%, and a total meat yield of 14.64%.

Susceptibility of Solanum melongena L/Solanaceae to Drought at Different Growth Stages

2023-11-04T16:58:42+00:00

The study on the susceptibility of Solanum melongena to drought at different growth stages was conducted in the 2019 and 2020 growing seasons. S. melongena is one of the most relevant agricultural crops in the tropics and subtropical regions of Africa. However, drought has a significant effect on the rate of growth and fruit yield of the crop. However, the growth stage at which S. melongena is vulnerable to the effect of drought needs detailed research and clarification which is the focus of this study. Key morphological traits such as shoot height, number of leaves and branches, and leaf area and water-related physiological indices such as leaf area ratio, net assimilation rate, root shoot ratio, tissue water content including aboveground biomass, leaf relative water content, chlorophyll pigments, osmolytes accumulation, and antioxidants were observed and measured to find the effect of drought at different growth level. The result revealed that the morphological traits, water-related physiological indices, aboveground biomass, leaf relative water content, photosynthetic pigments, antioxidants such as alkaloids and flavonoids of S. melongena were drastically reduced under drought throughout the growth period, associated with vegetative, flowering, and fruiting stage. Osmolytes such as phenol and proline were more enhanced. Across the growth stages, S. melongena subjected to drought at the vegetative stage has exhibited the lowest performance in the measured parameters and has the lowest critical value. S. melongena at the vegetative stage was more vulnerable to drought than the flowering and fruiting stage. Susceptibility to drought of the crop at the vegetative stage can lead to poor growth and yielding.

Contribution of Participatory Forest Management Program in Non-Timber Forest Products to balance Livelihood Improvement and Conservation: a case of Sera Forest, Amigna District, Southern Ethiopia

2023-11-04T17:19:05+00:00

Non-Timber Forest Products (NTFPs) have a significant role as a local source of medicine, fiber, forage, and sustenance and offer income opportunities mainly in rural families. As sustainable use of NTFPs is imperative to provide ecosystem services and biological resources, this study focused on the identification and documentation of plant species used for NTFPs, their availability, and conservation status in Sera Forest, Oromia Regional State, Ethiopia. The study applied a combination of plant ecological and ethnobotanical methods. Ethnobotanical data were gathered through semi-structured questionnaires and interviews which involved 206 randomly sampled general and 24 purposively selected key informants, group discussions, guided field walks, and market surveys. Data were analyzed and presented using analytical methods of ethnobotany, including descriptive statistics, informant consensus factor (ICF), and ranking. Species diversity, richness, and evenness were also computed using Shannon–Wiener diversity indices. A total of 137 plant species belonging to 49 families used as a source of NTFPs were documented from the study area. Eleven major use categories of the NTFPs were identified. Out of these, medicine, firewood, charcoal making, and construction materials were the most dominant uses requiring large volumes of NTFPs. Direct matrix ranking of plant species with multipurpose use revealed, that Hagenia abyssinica was ranked highest, followed by Olea europaea ssp cuspidata, Grewia mollis, Croton macrostachyus, Ximenia americana and Carissa spinarum. Local communities of the study area possess rich indigenous knowledge in the regulation of grazing and extraction of forest products, forest patrolling, firebreak clearance and maintenance, selective preservation of tree species and nursery activities focused on the restoration of indigenous woody species, which all help in using their natural resources for sustainable livelihood. Sera forest is rich in NTFP-bearing plants and associated indigenous conservation knowledge. However, nowadays illegal timber extraction, grazing, over-harvesting of NTFPs, farm expansion, and fire hazards are found to be threatening the plant resources, irrespective of the Participatory Forest Management (PFM) principles. Therefore, it is important to have strong evaluation and monitoring mechanisms for setting harvesting quantities and regulating types of collection. Besides developing a sense of ownership, and responsibility, integrating their traditional forest management practices with modern conservation approaches is desirable for higher livelihood outcomes with lower environmental impacts.

Effect of Polymerization Variables on the Electrical Conductivity of Polyaniline Functionalized Cotton Textiles

2023-11-04T17:43:02+00:00

Polyaniline functionalized cotton textiles were synthesized via in situ oxidative polymerization of aniline using hydrated ferric chloride solution in acidic media. Variation in conductivity was examined against polymerization variables such as amount of aniline, oxidant, reaction media, and time. Effects of polyaniline functionalization on the structural features of cotton textiles at optimum polymerization conditions were screened by FT-IR, TGA, and SEM instruments. FT-IR profiles at 1440 cm^-1 and 1560 cm^-1 proved the existence of benzoid and quinoid rings within the cotton structure, which confirmed the introduction of polyaniline in its conductive form, emeraldine salt. Thermal studies revealed the existence of polyaniline, which further enhanced the thermal stability of cotton textiles. SEM microstructure also proved the formation of nonuniform surfaces with a considerable amount of debris, buds, and channels due to the inclusion of polyaniline. Polyaniline functionalization has shown substantial enhancement of electrical conductivity by changing insulating cotton to semiconductor. At optimum polymerization variables ([aniline] = 1 M, [oxidant] = 1 M, [acid] = 0.5 M, and time = 24 hrs), maximum conductivity was registered at 7.63 X 10^-3S/cm, which is equivalent to the conductivity of semiconductor materials.

Structural, Dielectric, Complex Impedance and Magnetoelectric Properties of the (1-x) KNbO3 - xMgFe2O4 Composites

2023-11-04T17:52:00+00:00

Ferrite-ferroelectric nanoparticle composites have a promising potential for a wider range of applications for the manufacturing of new-generation devices due to the tenability of their electric and magnetic orders. In this present work, room-temperature magnetoelectric (ME) coupling studies of KNbO₃/MgFe₂O₄ composites having a general formula (1-x) KNbO₃ - xMgFe₂O₄ (where x = 0, 0.1, 0.3, 0.5, 0.7, 0.9, 1) is presented. The presence of the cubic spinel-ferrite phase of MgFe₂O₄ and the orthorhombic ferroelectric phase of KNbO₃ were confirmed by the structural analysis which was employed using X-ray diffraction (XRD), Raman spectroscopy, and morphology and grain size using Transmission electron microscopy (TEM). Magnetization versus magnetic field (M-H) measurements conform to ferromagnetic ordering and show improved magnetization with the increase in the ferrite phase. The existence of coupling between ferroelectric and ferromagnetic ordering was performed using a lock-in amplifier ME measurement setup. All the composite samples show good linear magnetoelectric coupling that increases with increasing ferrite content. This composite nanostructure with a well-defined interface provides the possibility of an ideal model of room temperature ME coupling which is significant from the technological point of view for a variety of miniaturized next-generation device applications.

Nano-Zirconia Synthesis Methods and their Pioneering Applications in Dentistry

2023-11-04T14:45:57+00:00

Nano-zirconia, also known as nanocrystalline zirconia or zirconia nanoparticles, is a versatile material with numerous applications in various fields, including catalysis, sensors, energy storage, and biomedical engineering. This review manuscript explores the synthesis methods of nano-zirconia, focusing on the sol-gel method, precipitation method, hydrothermal method, flame spray pyrolysis, and template-assisted synthesis. Each method is discussed in detail, highlighting its advantages and disadvantages. The selection of a synthesis approach depends on factors such as desired properties, scalability, cost, and equipment availability. Furthermore, the study examines specific dental applications where nano-zirconia materials find utility. In dental implantology, nano-zirconia implants have shown promising results in terms of osseointegration, with comparable or superior performance to titanium implants. Surface modifications, such as bioactive coatings, have been explored to enhance osseointegration and long-term success. Additionally, nano-zirconia ceramics have been utilized in dental prostheses, such as crowns, due to their biocompatibility and exceptional strength. Studies have evaluated the mechanical properties and translucency of different zirconia compositions for dental restorations. Moreover, improvements in the sol-gel process have led to the development of zirconia-silica glass ceramics with enhanced aesthetics and corrosion resistance. Lastly, the impact of professional tooth cleaning on zirconia dental prostheses has been investigated, providing insights into surface properties and bacterial adherence. Overall, nano-zirconia materials offer great potential in various dental applications, and their synthesis methods can be tailored to obtain desired properties for specific uses. Further research and optimization are required to fully explore and exploit the capabilities of nano-zirconia in dental settings.

An Engineering Geological Appraisal of the Leakage Problem in Dora-1 Earthen Dam, Tigray: Implications for its Stability

2023-11-04T15:10:39+00:00

Leakage is one of the major problems facing the functionality and sustainability of dams. It occurs through the embankment body, reservoir, foundation, and abutments. This study was conducted to identify the main causes of the leakage problem at the Dora-1 dam, located in the northern part of Ethiopia. It is an earthfill dam with a height of 43.5 m, crest length of 454 m, and reservoir capacity of 4.67 million cubic meters. Part of the embankment body was wet and swampy up to 20 m high from the ground due to leaking water. Geological investigation, laboratory test of the construction materials (including grain size analysis, specific gravity and water absorption, Atterberg limit, free swell, dispersion, permeability, and shear strength), and electrical resistivity investigation were used to identify and pinpoint the possible causes of the leakage problem. Results of the study show that the favorable geological features responsible for the occurrence of leakage include: (a) geological contact between sandstone and moderately to highly weathered basalt unit at the left abutment, (b) the gravelly sand deposit at the central foundation and (c) dyke outcrop at the river course within the reservoir running in the upstream-downstream direction. Results of laboratory tests for clay core show medium to high compressibility, good to poor workability, and semi-pervious to impervious permeability when compacted. The water absorption and the percentage finer of the filter material don’t satisfy the filter criteria and the shell material was found to be semi-previous. The anomalous in the resistivity survey result confirms the situation. Slope stability analysis of the embankment showed instability conditions at full reservoir level. Close follow-up and a downstream stabilization structure, including rock and gravel support, were recommended.

Construction material; Embankment dam; Site investigations; Ethiopia.